Process for refining and cracking oil



Jan. 18,1938. E. A. ocoN PROCESS FOR BEFI'NING AND CRACKING IL Filed March 8, 1937 Patented Jan. 18, 1938` UNIT-ED lSTATES PATENT 0F`FlCE` 2,103,013 PROCESS FOR REFNIEIG AND ORACKING 13 Claims.

This invention relates to treatments of bituminous materials, such as crude oils, topped crude mineral oils, materials from extraction, and liquefaction of coal, to form therefrom commercial products such as anti-knock gasoline, fuel oils and lubricants', by the use o a simple and iiexible arrangement of apparatus in which operations are carried out to permit ready utilization of ordinary wa'ste products, such as residues, polymerliquids and gases.

According to this invention, an economy in apparatus, space and handling of materials is obtained with the conservation of energy and materials, while at the same time, the apparatus can be adapted to treat various types of initial materials to obtain products which the initial material is most suited to produce or which the obtained by the use of heat evolved and put into n one reaction for aiding in carrying out another koperation which is generally necessary in reiineries, namely; distillation of initial charging stocks, with an enhancing of the eiiiciency and yield of the distillation, and elimination of or simpliiica-v tion of apparatus. At the same time, the result-g ing distillation products are especially suitable for further treatments or use and can be changed by merely making changes in operating conditions.

a A conservation in material is also obtained in that the heat evolving reaction is a hydrogenating reaction and can be used to transform by-products of the further. treatments into oils which can be mixed withfractions of the charging stock with bituminous liquids relatively free from compounds present in cracked materials in much larger quantities than in straight run petroleum products,

which compounds insofar as the complexity ofthe' material permits analysis, appear to be cyclic and unsaturated hydrocarbons, are subjected to distillation vto produce distillates and residual oils without substantial cracking and with'the aid oi heat and products from a hydrogenation treatment. Since the products from the hydrogenation are relatively saturated, this distillation is.

comparable to a straight distillation, especially with the aid of the gaseous products of the hydrogenation, in lowering the partial pressure ofthe (Cl. ISG-53) distillates. This results in the formation of a gas oil substantially unmlxed with cracked materials, which kind of oil iseasy to crack with low coke formation, in distillates lighter than gas oil which are easy to reform or dehydrogenate, and in heav- 5 which may beused for the hydrogenation are the 10 ready available by-products of the cracking, re-

forming, and purication treatments, to which the products of the distillation may be subjected. The term bituminous" is to be understood as meaning the materials are relatively highly saturl5 ated as in parainic hydrocarbons and naphthenic hydrocarbons. If extraction products, such as, rates from'extractions by solvents of the nature of sulphur dioxide, are used, vthey can be directly distilled, but when the more unsaturated 2`0 extracted oil in such extractions are used, which oil may be aromatic or unsaturated, such oil would rst be subjected to hydrogenation. Similarly, saturated liquid products of the liquefaction of coal, from shale oils, from heavy synthetic hydro- 25 carbon products produced by reaction of hydrogen with carbon monoxide, and products produced by saturating, partly or wholly, products from the polymerization of unsaturated hydrocarbons can be considered as coming under the term of bitu- 30 minous materials. Also natural asphalts, parafns, naphthenes, waxes, etc., in contradistinction to cracked hydrocarbon, aromatics, unsaturated hydrocarbons, and pyrogenous (cracked) asphaltic residues, such as arev obtained from cracking stills.

One obiect of the present invention is to provide a novel and eiliclentv process and apparatus to subject any residual product from cracking and reiining treatments imposed on hydrocarbon liq- 40 uids and vapors to a hydrogenation treatment in order to substantially saturate such residual productso that more valuable materials for use as lubricating oil, fuel oil, and cracking stocks are obtained, in a manner in which they can be readily vseparated by fractionation, while they at the same time can be admixed with fresh charging oil which they may aid in distilling by virtue of theirheat `content together with the vaporlzing effect of the gaseous\products of the hydrogenatiom A further object nf uns invention is to provide a novel method and apparatus for making a more eillcient use oi homogeneous catalysts or polymerizing agents through the use of a hydrogenation treatment on the residuals containing the used polymerizing agent or catalyst, in which hydrogenation, the used polymerizing agent or catalyst is of further use or at least is not objectionable.

A further object of this invention is to provide a novel and efllcient process and apparatus to utilize the ordinary waste by-products of `residues, polymer-liquids and gases in a novel method of distilling a fresh charging stock to produce a high octane gasoline substantially free of sull phur and gum forming substances.

A further object of the inventionis to provide a novel and eicient process and apparatus for the utilization of residual distillates such as Diesel fuel stocks or cracking stocks, especially when the initial vcharge is more suitable for making fuel oils than lubricating oils, and especially with the distillation involving some viscosity breaking, and with the recovery of more desirable products from the heavy unvaporized residue by hydrogenation if its components are deficient in hydrogen.

A further object of this invention is to provide a novel and eilicient process and apparatus for the utilization of residual oils and heavy residual distillates, obtained especiallyv when the distillation is performed on suitable charging stocks, such as, parailin or mixed base crudes without appreciable cracking as lubricating oil stock: which can be readily refined by ordinary chemical treatments, such as aluminum chloride, zinc chloride, boron fluoride or solvent extraction, making possible a good recovery of the otherwise wasted gummy oils.

A further object of this invention is to provide a novel and eiiicient process and apparatus for the utilization of the lighter distillates. such as, the gas oil, kerosene and naphtha for cracking and reforming and to separate out the products from these operations unsuitable for motor fuels but may be hydrosenated to make possible the recovery of more suitablel products.

A further object of this invention is to provide a vnovel and eillcient process and apparatus for advantageously utilizing the heat energy of residues and waste products more eiliciently than they have hitherto been used to distill a fresh charging stock and provide an especially suitable treatment of ordinarily wasted by-products which can be used in conjunction with the distillation to aid in the removal oi sulphurous and other-in- Jurious compounds from the cracked vapor prod- The process will be describedwith reference to the accompanying drawing, in which:-

` The figure diagrammatioally illustrates theconventional apparatus involved.

'I'he charging stock from any suitable source is passed by linel by means of a pump (not shown), through-a heat exchanger 2 and 3 to `either of the valve joined lines 5 or 53. preferablyto 5, which leads into the flash distillation tower 6. In the lower part of said tower I the charging stock, preheated by heat exchange, is discharged intola blast of products from a hydrogenation zone 1, which products include large volumes of heavy naphtha, and a lighter gnaphthafifraction with regulation permitting light ends of gasoline and normally gaseous materials to pass overhead.

'I'he residual oil distillate will have a suitable v raising the temperature of the gas oil to about' '750 to 900 F., the oil being maintained in a vapor or partly vapor and liquid state at these temperatures for a period of 10 to 2 minutes, with less time as the temperature 'is increased, and a pressure of about 30 to 350 lbs., per square inch. The thus treated gas oil products are sent by a valved line to an enlarged zone 30, where vapors are separated from liquids and time for further reaction may be given. Methanol synthesis products can be used for quenching the cracking products passing from the cracking unit 25 to the separator 30.

'I'he fraction of the nature of kerosene mixed with heavy naptha is led by valved line I8 to a reforming unit, conventionally shown, and designated by 24, which may be a system of heated tubes, or heated tubes connected with an enlarged zone for containing catalysts. The lighter naphtha cut may also be passed together with the kerosene cut by valved line 20 and valved line Il to the reforming unit. When no catalysts are employed the oils are subjected to heating to a temperature of about 1000 F., at a pressure of about 400 pounds per square inch for a sufllcient period to form anti-knock constituents without too much gas, say a period of less than two minutes. When a catalyst is used, such as activated alumina, activated magnesia, chromium oxide, potassium oxide, limestone, halogen compounds, diiilcultly reducible oxides, such as' oxidizable metals with halogens or other oxidants, halogens with metal oxides, or other diiilcultly reducible oxides alone or promoted. by other oxides such as alkaline oxides which increase porosity and prevent sintering, lower temperature and pressures and shorter periods may be used. In particular, with sensitive catalysts, such as copper-nickel, cobalt, iron-copper, and similar metals or their mixtures which cause mainly a dehydrogenation reaction, the temperatures may be as low as about 850 F., and the periods less than one minute; that is, with space velocities of one volume of vapors per minute. per volume of catalyst space, approximately. It may be preferable to subject only the lighter naphtha cut to the dehydrogenation with the use of sensitive catalysts, especially when the cutis free from poisons which may be removed by the hydrogenation and other chemical treatment im- .posed upon the oil, and in this event, the heavier naphtha and kerosene oil can be separately reformed to obtain splitting; for example they may be passed through valved line I6 to join the gas oil passing to 25, which is operated in this event at high vapor phasecracking temperatures. 'I'he products of reforming may also be sent to enlarged zone ll or be by-passedby line 21 to a fractionator 32. Vapors from'zone 3l pass by line 51 and through valve 22 to the fractionating tower 32, in which constituents higher boiling than gasoline constituents are reiluxed out. 4A kerosene reflux may be' collectedl in an intermediatefsection ofthe fractionator to be recycled to the reforming unit to increase the anti-knock and or cracked products passed to separator gasolineby-product by a line (not shown) leading from the fractionator 32 to the reforming unit 24.

Overhead vapors and gases from tower 6 may be passed by line 2| to join either the .reforming 30,v by, valved line 28 or valved line 21, or the vapors entering the fractionator 32, or be made to bypass the fractionator and a clay treating zone 36, by valved lines `5|! and 35. 'I'he by-passing of the fractionator and treating zone is preferable when the light gasoline vapors contain too much gas and particularly sulphur compounds.

The overhead gasoline vapors from fractionat-or 32 may be led by line 34 to a treating tower 36 which may have an inlet (not shown) and. an acid. treated clay 36 or metal salt such as zinc chloride or tin chloride, or other adsorbents and chemicals to remove gum forming constituents and other undesirable substances, and from 36, the purified gasoline vapors are led by line 38 through heat exchanger 2 to a condenser 39, to condense out a gasoline product. The.con densate and uncondensed material is passed from the condenser to a receiver 48 for separation of the liquids from uncondensible vapors and gases. The gasoline is Withdrawn from the system through valved line 23.

Liquid polymersformed in the treating tower 3B, reflux condensate fo-rmed in the fractionator 32, and residual liquids separated in 30 may be passed by lines 43, 33 and 45, respectively, to a hydrogenation unit 1, conventionally shown, to be subjected to hydrogenation individually, intermixed one with the other or others, or with other residual oils of the operation. Line 44 is a means. for conveying the above mentioned liquids to the hydrogenation unit 1, and a pump (not shown) may be provided for increasing the pressure on the liquids. The hydrogenation unit 'l may be constructed of heated tubes, or heated tubes leading Ato an enlarged zonejwith catalysts in the tubes, the enlarged zone, o r both. Hydrogen, hydrogen-containing gases; or hydrogencus gas or vapor is supplied to the hydrogenation unit. Recycled uncondensed gas such as removed from receiver 40, may be led by line 4| to a heating or gas decomposing coil 42, thence to" the hydrogenation zone, or steam, or steam jointly with reducing gases may be used, especially with agents capable of decomposing the steam. About 600 cu. it. of hydrogen or more may be used per gallon of liquids treated. Temperatures of 500 to 900 F. may be used; pressures may range from about 5 to 20 atmospheres and higher. Catalysts to be employed vin the hydrogenation are metal halides or metal oxides, such as Iiron omde, magnesia or nickel oxide;l metal sulphides such as cadmium sulphide, molybdenumv sulphide. or tinnediro-n.

etc. The catalysts may be xed in the reaction zone, as on carriers of charcoal, activated carbon, or clay, or be suspended in the oil treated in amounts of 1 to 10% of theoild The hydrogenation reaction is controlledI so that small amounts of gasoline are formed, especially when a saturated product is desired. The time of reaction is about 1 to 5 minutes, or more.

Products from the hydrogenation may be sent by valved line 29 to the separator 30, or a portion may be so sent, but preferably they are led'by y linev 8. through valve 9 into the` lower part of tower 6, being discharged through .spray I 0, from which vapor andv gas products ascend to aid in the distillation of liquids, discharged into tower 6. Unvaporized residuals collect at the bottom hydrogenation v n morey rigorous conditions and the tower 6 kmay cr 6, 'other than the heaviest,

of tower` 6, and may be withdrawn through ,i

valved line l2 to be resubjected to hydrogenation or to be used as fuel oil or, when of high quality, to be used for obtaining lubricants. Especially, when the initial charge oil is of high quality, such as, a paraiiin base or mixed base crude products, and other oils entering tower vl as from the hydrogenation zone are highly saturated, residual voils may be led by valved line 59 to chemical treatment units. 'I'he residual oil may first be subjected to a dewaxing, if necessary, and then treated in vessel 48 with a refining agent, such as aluminum chloride', zinc chloride, boron fluoride, at temperatures of 200 to 450 F., the aluminum chloride being led into 48 admixed with oil through line '41 and stirred with the` oil to be treated for about 4 hours or over. The aluminum chloride should be used in amounts of about 2 to 10% of the oil treated, depending upon the amount needed. Vapors generated may be returned to the tower 6 by line G0. Following the treatment in 48, the rened oil is decanted vessel 49, and separated thus I2 to the hydrogenation zone 1. In 49 the aluminum chloride treated oil is washed with about 9% of concentrated sulphuric acid, or about that amount of a 98% sulphric acid which may be led through valved line 3|. It is then passed through line 5l into vessel 50 to be further washed with water and caustic soda led through valve line 5| to neutralization, and then blown bright or reduced in 52, with steam at above 500 F. to obtain the desired viscosity. The oil is then passed through line 62, heat exchanger 3 and condenser 56 into the receiver 54 from which it is withdrawn from the system. Clay may also-be used yin`the distillation. Any wax separated in dewaxing may be used as charging stock for the cracking unit, since it is of highly saturated nature. To aid in removing volatiles from the-treating vessel A48 and in forming some desirable 4polymers in the lubricating oil, normally gaseous hydrocarbons from the cracking operation may be led into vessel 48 through valved linel 58. The sludge,

containing .partiallyspent aluminum chloride,`

can'he` readily subjected to hydrogenation in 'l through valve line 6|, for the aluminum chloride itself will still have catalytic activity, and even with water present which hydrolyzes it to alumichlorideemay be used, and in some cases other treatments such as with solvents which extract asphaltic constituents may be used, and in the solvent treatments solvent tars are recoverable which may be sent to the hydrogenation unit.

When the initial stock is or' 'lower quality, it

may rst be partly directed, asby liner |2 to the hydrogenation zone, and partly by .line 5 to discharge into tower 6. In this instance, the zone may be operated under-little have what approaches to a viscosity. breaking at its base. More naphthenic,v mixed base, or somewhat asphaltic base crude oils would vbe considered as having lower quality. The operations with regard to the distillates formed in tow- `ay remain the same as described, but the hea v tilled residuals, may be of such quality to be useful as Diesel fuels, or otherwise as cracking est, `called disstock which may be treated in the cracking unit 25.

Charging stocks which come into contemplation -for use besides crude and topped crude mineral oils 'are bituminous materials from extractions, liquefaction of coal, shale oils, products of water gas synthesis, polymerized products, etc.

Besides the hydrogenous gases mentioned for use in the hydrogenatlon, it is contemplated that other reducing gases or vapors, such as water gas, methanol, and natural gas, etc., can be used. When steam is used, it is preferably superheated. mixed with a reducing agent such as carbon monoxide, hydrocarbon vapors. or the like, and

in the presence of decomposing contact materials,

such as hydrides of calcium, spongy iron, alloys of chromium, etc. Methanol and other low alcohols have beenlfound very suitable because they4 decompose at low temperatures to liberate hydrogen and carbon monoxide, especially in the presence of catalytic agents such as zinc oxide, vanadium oxide, copper, iron oxide, nickelalumina, zinc oxide-chromium oxide, etc., which while present in the hydrogenatlon zone also may accelerate the hydrogenatlon of the oils, and at the same time alcohols appear to have alkylating `effects desirable in the final products.'

In the gasoline treatment may also be used meta1 halides, such as aluminum chloride, zinc chloride, etc., especially, since by providing of the hydrogenatlon, use can be made of the particular spent catalyst. A

I'he exact sizes of apparatus and conditions depend upon the capacity of the plant. the character of the charging stock, and types of products desired. Instruments, valves, pumps and other of such engineering equipmentare not all mentioned, but it is understood that they will be used as required and as understood in the art.

'I'he polymerization in tower 36 is mainly one carried out to free the gasoline vapors from gum forming constituents such as 'dioleflns. 'I'he chemical polymerlzing agent such as clay, metal halides, or whatever is used, causes the highly unsaturated hydrocarbons such as the diolens to vpolymerlze into tarry oils, which may be led to the hydrogenatlon zone 1. where they can be treated to form more saturated oils. These more` saturated oils are valuable in that a portion can be -used to form lubricating oil, fuel oil or Diesel fuel, that is, the .portion remaining as residual oil or heavy reflux in tower I, while the lighter saturated parts are susceptible to more ready cracking and reforming without excessive coke formation. This treatment therefore makes possible a good recovery of the otherwise wasted gummy oils from the polymerization treatment in- Having described myinvention, what Iclaim and desire to secure lowsz- I I 1. A Iprocess for vtreating bituminous materials such as mineral oils of wide boiling .range substantially free from cracked materials `to produce' cracking. stocks and Lvaluableiiesidual'oils. which comprises vaporizing 'the initial bituminous by Letters Patent, is as folcnerging am with the aid of unipr-udma from 4 a saturating hydrogenatlon of hydrocarbon oils decient in hydrogen by directly contacting said products while hot with the bituminous oil undergoing vaporization to form vapors and residual products, and fractionating the vapors to form non-refractory cracking stock distillates and valuable residual stocks substantially free from cracked materials.

2. A process for treating bituminous materials to produce high4 quality lubricating oils, comprising subjecting initial bituminous oils containing lubricating oil constituents to vaporization with the aid of hot products of hydrogenatlon by directly contacting said hot products with the bituminous oil undergoing vaporization to produce vapors and residual oils, subjecting residual oils of the vaporizatlon to rening to produce reilned lubricating oils and undesirable tars, subjecting tars separated in the refining to hydrogenation to produce more valuable saturated products, and using products of the hydrogenatlon for aiding the vaporlzation of the initial oils as hereinbefore stated.

3. A process in accordance with claim 1, in which non-refractory distillaies higher boiling -than gasoline are formed in the fractionation and are subjected to cracking conditions to pro- ,duce gasoline, passingl products of the cracking to a separation zone to separate vapors from liquids, subjecting vapors separated in the separation zonev to fractionation to condense out liquids higher boiling than gasoline and to obtain overhead gases and vapors of the gasoline range, subjecting liquids condensed out in the fractionation to hydrogenatlon without substantial cracking, and using products of the hydrogenatlon in aiding the vaporization of the initial oils in the vaporization zone by directly contacting said hydrogenated products while hot with the initial bituminous oil undergoing vaporization.

4. A process for treating bituminous materials,

' such as mineral oils of wide boiling range. which comprises subjecting the initial oils to vaporization with the aid of the products of hydrogenation,fractionating the vapor's formed in the vaporization to produce a condensate intermediate gas oil and light gasoline, subjecting the intermediate condensate to reforming to produce anti-knock gasoline constituents, separating out liquid products of the reforming boiling above .the desired motor fuel end point, hydrogenating liquid products thus separated without substantial cracking, and using products from the hydrogenation -while hot to aid in vaporization of the initial oils by directly contacting said hot kproducts with the initial oils undergoing vaporization.

5. A process in laccordxalnce with claim 4, in which residuals formed in the vaporisation are subjected to refining to produce refined oils and tars, separating the tars from the renned oils, subjecting tars thus separated to hydrogenatlon without substantial cracking with liquid products of the reforming. boiling above the end point of the desired motor fuel, and using said hydrogenated products while hot to aid in vthevaporis'ation of the initial oils by directcontact therewith.

6. A process for treating bituminoi materials, such as mineral oils of wide boiling range,which comprises subjecting the initial material to va- 'porization with the aid of products of hydrogenation, separating' vapors from liquids produced in the vaporization, fractionating the vapors to produce cracking stock condensates containing tion to chemical treatment to polymerizev out gum forming constituents as liquid polymers, subjecting liquid polymers from the chemical treatment to hydrogenation without substantial cracking, and using products of the hydrogenation to aid in the vaporization of the initial material by directly contacting said hydrogenated products while hot with the initial material undergoing vaporization.

7. A process in accordance with claim 6, in which hydrogenation products are mixed with the cracked products of cracking prior to separation of liquid products.

8. A process for treating bituminous materials, such as mineral oils of Wide boiling range including gasoline constituents, comprising subjecting such initial material to vaporization with the aid of hot products from a non-destructive hydrogenation by directly contacting said hot products with the initial bituminous material undergoing vaporization, separating the vapors from liquids unvaporized, fractionating the vapors to procure cracking stock condensates and overhead light gasoline ends and normally uncondensed Vaporous and gaseous materials, subjecting cracking stock condensates thusl produced to cracking Without destructive hydrogenation, separating vapor from. liquid products of higher boiling range point than gasoline of the cracking, treating separated vapor products of cracking with a polymerizing agent to remove polymerizable constituents, then blending the reined vapor products of cracking with the light gasoline of the overhead products.

9. A process for treating bituminous materials, which comprises subjecting the initial bituminous materials containing gas oil constituents to vaporization with the aid of hot products of a saturating hydrogenation, ractionating vapors formed in the vaporization to form a distillate for cracking, subjecting the distillate to a heat treatment under cracking conditions to form gasoline constituents, separating out vapor products of the cracking from the liquid products of the cracking in a zone distinct from the zone in -which the initial materials are vaporized,sub jecting liquid products of the cracking of higher boiling range than gasoline to a saturating hydrogenation, and using products of the hydrogenation while hot-to aid in the vaporization of the initial materials by direct contact therewith.

10. A process for treating bituminous mate-l rials, such as mineral oils of wide boiling range including vcracking lstock fractions, comprising subjecting such initial materials in a preliminary zone to distillation by direct contact with hot uncracked hydrogenated products to produce a distillate cracking stock and a residual oil, subjecting a portion of the distillate to cracking under cracking conditions to form a motor fuel product, subjecting a portion of the residual oil to a saturating hydrogenation without cracking, and passing hot products from the cracking and hydrogenation to a separation zone to separate mixed vapor products of motor-fuel boiling range from liquid products.

11. A process as in claim 10, in which liquid products from the separation zone are ysubjected to a saturating hydrogenationA jointly with a portion of the residual oil and a portion of the hot products from thev hydrogenation are used to aid in the vaporization of the initial material.

12. A process for treating bituminous materials, such as mineral oils of wide boiling range including cracking stock fractions, comprising subjecting such material in a preliminary zone to distillation to produce a cracking stock distillate and a residual oil, subjecting such residual oil to a saturating hydrogenation without cracking to add hydrogen to constituents deficient in hydrogen, and passing the resulting products while hot into direct contact with the initial materials to aid in the vaporization of said initial materials and ractionating the vapors formed in said vaporization to produce said cracking stock distillate.

13. A process for treating bituminous materials which comprises subjecting a bituminous material of a type suitable for cracking or catalytic reforming' to heat under conversion conditions to produce anti-knock gasoline, subjecting vapor products of the conversion to a chemical treatment with a metal halide type catalyst to remove polymerizable constituents as, liquid polymers, subjecting such liquid polymers to a saturating hydrogenation without substantial cracking to produce saturated hydrocarbons of higher boiling range than gasoline, and using a portion of said saturated hydrocarbons as at least part of said bituminous materials subjected to conversion.

ERNEST A. OCON. 

